So, this time, I will give a few advice to everyone out there who seek to improve their skill... because I have been asked many times for this one but nobody heed my advice, so this is my answer folk:

1. Practice.(what else?)
2. Don't rely on those "how to draw manga" book, it DOESN'T work, for god's sake...
3. When reading a comic, try to pay attention to their anatomy and body structure...
4. Don't let anyone else to "repair" or "fix" your drawing, your drawing is good on it's own way....
5. Last but not least, don't give up, no one can run if they can't crouch first... be patient...

And some of my friend recommend this deviant account too,
http://www.deviantart.com/#/dgbgxs
Perhaps you should take a look on it...